Yima (simplified Chinese: 义马; traditional Chinese: 義馬; pinyin: Yìmǎ) is a county-level city in Henan, China. It is under the jurisdiction of Sanmenxia, located in the west of Henan province. Since ancient times, it had been a key stopover between Luoyang and Changan. In the 20th century, it became a wealthy city thanks to the mining and processing of coal.

The history of Yima's estabishment could be traced back to the Xin'an county of Qin dynasty. In 1981, it bacame the first county-level city in Henan. It was originally under the jurisdiction of Luoyang, since 1986, it has been under the jurisdiction of Sanmenxia. It has been listed several times as one of China's top 100 counties in terms of basic economic competitiveness. It is the smallest city in China (112 square kilometers with a population of about 140,000).

Relying on its own resource advantages, Yima vigorously develops heavy chemical industry, bringing rapid economic growth. In 2010, the city's per capita GDP was over 70,000 RMB, which is about US$10,000, and ranked No.1 in terms of county economy in Henan Province (perennially ranks top five). The city is also known as "The Home of Martial Arts".

Coal mining and processing dominate Yima's economy, and the Yima Coal Industry Group is the city's largest employer. At its peak in 2004, 76% of the local economy depended on coal. Since 2014, closures of several local coal mines due to national efforts to address coal overcapacity have contributed to an economic decline in Yima. In 2019, 15 were killed by an explosion at a gas plant operated by Henan Gas Group in Yima.

Yima is located in the western part of Henan Province, China, and lies between 34°42' - 34°46' north latitude and 111°50'47" - 111°50'49" east longitude. It is 183 kilometers east of Zhengzhou, the provincial capital, and 65 kilometers west of Sanmenxia.

Yima is located in a warm temperate zone, on the southern edge of the North Subtropics. There are four distinct seasons and abundant sunshine. The average annual temperature is 12.4°C. During July, the hottest month of the year, the average temperature is 25.5°C. In the coldest months, the average temperature is -2.1°C. The average annual amount of sunshine hours is 2250.4 hours, with an average annual sunshine rate of 51%. The area experiences southeastern winds in spring and summer, and northwestern winds in autumn and winter. There has abundant plant and animal resources, with an average annual rainfall of 666.9 millimeters.

As 2012, this city is divided to 7 subdistricts.

Subdistricts

Qianqiulu Subdistrict (千秋路街道) Chaoyanglu Subdistrict (朝阳路街道) Xinyijie Subdistrict (新义街街道) Changcunlu Subdistrict (常村路街道)

Taishanlu Subdistrict (泰山路街道) Xinqu Subdistrict (新区街道) Dongqu Subdistrict (东区街道)

G30 Lianyungang–Khorgas Expressway, China National Highway 310 both pass through Yima. Zhengzhou–Xi'an high-speed railway, andLonghai Railway also pass through Yima.

By the end of 2022, Yima City had 2 Major Historical and Cultural Sites Protected at the National Level and 3 cultural heritage sites under provincial-level protection.

• Hongqingsi Grottoes
• Chu Pits Site

The site where Xiang Yu had the 200,000 surrendered Qin soldiers buried alive. The site covers an area of 70 to 80 Mu. In 1912, workers constructing the Longhai Railway unearthed large amounts of ancient human remains from here. The built railway goes throught the site, and the original look of the pits no longer exists.

• Empress Cixi's temporary residence

During the Battle of Beijing, Cixi and Guangxu fled Beijing and evacuated to Xi'an as the Eight-Nation Alliance invaded the city. The temporary residence was built when they stayed shortly in this area on their way back to Beijing from Xi'an, more than a year later.

• The Old City of Qin Xin'an

Yima's Ginkgo Fossils

In recent years, archaeologists discovered the site, which contains the world's oldest Ginkgo fossils. One of those fossils has been dated to 1.8 million years ago, this date was confirmed in the International Organization of Palaeobotany's sixth and seventh conferences.